Push-button tuner



Ap 1945- LE ROY J. LEISHMAN 4 2,374,293

rusn BUTTON TUNER Filed June 17, 1941 V 4 Sheets-Sheet 1 Fig.1 l' E F5 F4 April 24, 1945- LE ROY J. LEISHMAN I PUSH BUTTON TUNER Filed June 17, 1941 4 Sheets-Sheet 2 P 1945- LE ROY J. LEISHMAN 2,374,293

PUSH BUTTON'TUNER Filed June 17, 1941 4 Sheets-Sheet 3 ZII INVENTOR.

M 1945- LE ROY J; LEISHMAN 2,374,293

PUSH BUTTON TUNER Filed June 17, 1941 4 Sheets-Sheet 4 Patented Apr. 24, 1945 Y PUSH-BUTTON TUNER Le Roy .7. Leishman, Los Angeles, Calif. Application June 17, 1941, Serial No. 398,502

'4 Claims.

This application is a continuation in part of my application Serial No. 179,439, filed December 13, 1937, and a continuation in part of my application Serial No. 149,442, filed June 21, 1937, issuing June 17, 1941, as Patent No. 2,246,050, and which, in turn, was a continuation in part of application Serial No. 757,644, filed December 15, 1934.

The invention herein described relates to automatic tuners, and more particularly to those in which a plurality of independently movable positioning means turn a rotatable member to difierent predetermined positions. The objects of this invention are to provide means for operating a mechanical tuner electrically; to make it unnecessary to reverse the motor; to reduce the number of electrical contacts to a minimum; and to achieve these various objectives with apparatusv that is simple and inexpensive. Still other objects will appear as this specification proceeds.

In the accompanying drawings:

Fig. l is a' front elevation and. diagrammatic representation of electrical means for operating automatic tuners oi the type having individual selectors for each of a plurality of stations. The

' ponents of Fig. 4.

Fig. 6 is a schematic diagram of a modification of the electrically operated tuner, showing a muting arrangement and means for shunting .the motor from the circuit when the tuning operation is completed. v

Fig. 7 shdws two positions .of one positioning device audits associated positionable member.

showing a pair 01 selector-solenoids adjustably mounted thereon.

Fig. 11 shows disc A of Fig. 9, together with the driving arms and other details.

Fig. 12 illustrate a modification of the apparatus shown in Fig. 11.

Positioning lever Fl, Figs. 8 and 9, is pivoted on rod Q, which is journaled at one end in endplate Cl, Fig. 1, and at the other end in endplate C2. Lever Fl, Fig. 7, is shown about to engage positionable member Al, which may be of the type shown, or any other type adapted to lever control, such as the heart-shaped cams of Vasselli, Patent No; 1,846,289, the internal cams of Bird, Patent No. 1,925,651, the reciprocating racks and bar of Schaeier, Patent No. 1,906,106,

or the positionable member of myown Patent No. 2,084,851. Positionable member A has a setscrew R and is one of a plurality of such members mounted in predetermined angular positions on shaft SI, and each is adapted to be engaged by one of a plurality of positioning levers, Fl to F4, Fig. 1. Solenoids or magnets 32a, 32b, 32c and 32d, Fig. 1, are mounted on lugs 28a, 29b, 29c and 29d respectively formed on levers Fl, F2; F3 and F4 respectively. Each solenoid'is equipped with a plunger P, having a flanged end or shoulder I, and each plunger is surrounded by a spring J pressing end I against abutment bracket E attached to thesolenoid or lever. Each lug 29 has a hole 33, Fig. 2 in alignment'with hole 34 in hub H, ,and the lower end of plunger P extends normally not only through holed-3 but also part way through hole 34 in the hub. Shaft Q, on which the levers Fl to F4 are pivoted, has a series of holes 35, Figs. 2 and 3, extending at least part way through the shaft; and each hole upon rotation of shaft Q, moves in the plane of a the corresponding hole 34 in one of the hubs, and

will of course come into alignment with hole 34 when shaft Q is in a suitable angularposition.

Fig. 8 shows in full lines the positionable memher in the opposite extreme of its possible angle A gear train 35 operatively connects shaft Q with motor :1 through friction clutch :a, the

plates of which are held in engagement by spring J3. Condenser shaft S2 is operatively connected to the rotatable positionable means and the usual manual drive in any suitable'manner, but

no connection is shown because: "(1) a satisfactory connection is illustrated in. Fig. 2 of my application SenNo. 179,439; and (2) the positionable means per se is not a part of this invention. s

spectivcly, and have contacts 4la, 4'" He and I Push buttons 40a, 40b, mand 40a are mdividual to solenoids 32a, 32b, 32c and 32d're- 4l d that are connected to these'solenoids respectively by wires 42a, 42b, 42c and 42d respectively.

'A return circuit for solenoids 42a, 32b, 32c and am is provided respectively by wires 43a, 43b, 43c and 43d all connected to wire 44 going to the motor. Motor 31 has a return wire 45 connected to'current supply 46, which is of any type adaptable to the variou requirements of the motor, solenoids and radio receiver. The other side of the current supply is connected by wire 41 to switches 40a, 40b, 40c and 40d.

If one of the push buttons, say 40b, is pressed down, the current will flow from source 46 through switch 4012, contact 4lb, wire 42b, solenoid 32b, wire 43b, wire 44, motor 31, and wire 45 back to source 46. This will energize solenoid 32b and the motor. The solenoid will then pull down on its plunger P, holding the lower end against shaft Q until it has been rotated by motor 31 and the interconnected gear train to a position at which the corresponding hole 35 comes into alignment with the plunger,'which the energized solenoid will'then force into hole 35. This locks the lever to shaft Q, causing the lever toturn with the shaft. If the positionable member is found in the position shown in full lines in Fig. '7, the'down ward movement of the lever causes it to turn in a counter-clockwise direction to the position shown in dotted lines. If the positionable member happens to be in any position between that shown in full lines in Fig. 8 and the tuned-in position, the lever upon its downward movement turns the positionable member in a clockwise direction to the final tuned-in position shown in dotted lines in both Figs. '7 and 8. Solenoid 32b andlever F2 are shown in Fig. 1 in the position to which they are turned whenthe solenoid and motor are actuated. The stoppage of the lever prevents the further rotation of shaft Q, but excessive strain on I the motor is avoided by the fact that clutch 38 can slip until the operator removes his finger from the push button. When push button or switch 40b is thus opened, the motor no longer exerts any torque on shaft Q, and spring J on solenoid 32b forces the plunger upward and the lower end of the plunger moves out of hole 35. The subsequent pressing of any other push button'will in like manner energize the motor and another solenoid which will lock its associated lever to shaft Q and thus operate the lever and tune in the proper station. a

A tuner of this typ may be adjusted in the following described manner so that the pressing of any button will bring in a, predetermined station.

One of the push buttons, say 40a, is pressed down,

causing the positionable member to. move to the position shown in dotted lines in Figs. .7 and. 8. While the button is held down, set-screw R is loosened by means of a screw driver inserted through hole U in plate 21, which may be used to connect end-plates Cl and '02, Fig. 1. The loosening of this set-screw permits shaft SI to turn freely while member Al is held stationary. The desired station is then tuned in by means of the regular manual knob, not shown. rotating shaft S3 and transmitting the motion to condenser shaft S2 by the interconnecting means previously mentioned. After the desired station has been carefully tuned in, setescrew R is again tightened. Other positionable members are then adjusted, or set. in like manner so that the pressing of the associated buttons will thereafter bring in preselected stations. If different positionable means are used, the appropriate adjustments are similarly made. Regardless of the type of lever-controlled positionable means employed, it will be obvious that the pressing of any button will cause the associated positionin means to return the shaft to the angular position that it occupied when the initial tuning operation was performed.

In the simple electrical tuner just described, it will be observed that it is never necessary to reverse the motor. In some tuners heretofore on themarket, difilculty arises if the operator inadvertently presses twobuttons at the same time. In thi mechanism, the operating levers rest in various positions on the positionable means, according to their individual adjustments, and therefore if two solenoids are simultaneously energized, the first lever to become engaged with the shaft will complete its tuning action unless the rotation of the positioning means is stopped by force applied to the positioning means in an opposite direction by the next lever to become engaged, and in that case no harm results as nothing happens until the operator realizes his error and removes his finger from one of the buttons.

Fig. 4 is a diagrammatic representation of an automatic means for shunting the motor out of the circuit the instant any positioning lever has completed its downward movement. In this modification. the clutch 38 of Fig. 1 is replaced by clutch 5|, which may be located in any suitable part of the transmission between the motor 31 of Fig. 1 and shaft Q. Members 52a and 52b are shaped like the two halves of solid cylinder or piece of shafting cut diagonally. Member 52a is mounted on tube 53 and attached thereto by means ofscrew or pin 54. Tube 53 is longitudinally movable on shaft Q3, and is locked against rotation by pin 55 in slot 56 in the tube. A spring J4 abutting against pin 55,holds member 52:! in engagement with member 52b attached to shaft Q by pin or screw 51. Shaft' Q3 is the driver, and may be the motor shaft itself or an auxiliary shaft driven by the motor. Shaft Q may be the shaft upon which the positioning levers are pivoted, or it may drive this shaft through a gear train or other means. As long as this shaft turns, which it will do while moving a positioning lever, the diagonal sides of members 520 and 52b will remain in contact and single pole single throw switch 58 will remain open. One side of this switch is connected to wire 44 by means of wire 44a, and wire 45a connects the other side of the switch to wire 45.

When a. positioning lever has moved to the position in which lever F2 is shown in Fig. 2, the stastopping the motor. No diiiiculty arises if the operator continues to hold the push-button down. The motor is no longer energized, because the clutch remains in the position shown in Fig. 5 as long as the current flows through the solenoid, keeping shaft Q, locked to lever F2, which has reached the limit of its movement. The action of spring J4 on member 52a cannot force Q8 to turn in order to permit the, clutch to close, as the gear train provides too great a load. When the pushbutton is released, however, spring J on the solenoid forces the lower end of plunger P out of shaft Q.. Spring J4 on the clutch then exerts sumcient pressure on member 52a to rotate member 52b and shaft Q until the clutch closes and permits the motor shunt switch-to open. The mechanism is then again ready for operation when the next push-button is pressed.

Unless an electric tuneris very rapid in its operation, some sortof muting device is required. If the motor haslittle torque, necessitating great reduction in the gear train, a muting arrangement is advisable on the present tuner. A simple muting means is shown in Fig. 6, in which bar 48 is made of insulating material. This bar extends all the way across the device and therefore lies in the path of all the positioning levers. The bar has a pivot Q2, which may extend all the way across the tuner to permit the two ends to be attached to the end-plates, or elseseparate pivots may be arranged in axial alignment at the two ends. free edge of the muting bar, and a stud or rod 60 is so positioned on the end plates that strip 49, held against stud 50 by theaction of' spring J5, is .iust free from engagement with any positioning lever when all. the levers are in their inactive positions against resilient bumper 6|, which may be a rubber tube upon a rod 62. This position of the muting bar is shown in dotted lines.

a spring J S, the other end of which is attached to a rod 63, extending from one end plate to the other, and this spring holds the lever against the bumper and out of engagement with strip 69.

Upon slight downward movement, however, any positioning lever will engage this metal strip.

The positioning levers themselves are formed of metal and are consequently automatically grounded to the chassis. Engagement with the contact strip will therefore mute the set if wire 50, connected to this strip, is also connected to th antenna post or to any other part of the receiver, which, if grounded, will effectively prevent the operation of the set. 1 The muter is, of

course, disconnected when the lever is drawnupward to its'rest position after the tuning operation. a

The muting bar of Fig. 6 may be used to operate a switch that willshort the motor out of the circuit just before the tuning action is completed.

' The momentum of the motor and other rotating parts then turns shaft Q and the positioning lever through the few remaining degrees of -.its throw. As lever F2 nears its furthest downwardlposition,

' the insulated portion of muting bar 48 engages tappet 59 of witch 58, pressing the contacts together. one side of the switch is connected by wire fl'fiato wire '40, and the other contact of the switch is connected by means of wire 45a to wire 45. Wires 64 and 35, as shown in Fig. Lare the wires that go to the motor, and it will thus be seen that the closing of this switch short the circuit around the .motor, permitting the solenoid to remain energized and retain the lever in connection with shaft Q until the tuning action is removes his finger- A metal contact strip 49 extends along the Each positioning lever, when a muting bar is used, has

connecting the lever with the motor-driven memben. a

Figs. 9 to 12 show a different embodiment of the invention from that illustrated in the previous. figures. This mechanism may be used for positioning either a singletuning shaft or two independent shafts, in which latter case the shaft may be turned to difierent and unrelated angular positions. Should it be desired to broadcast television images and the accompanying sound on unrelated frequencies, disc C, Fig. 9. may be considered as operating a television tuner, and is mounted on hollow shaft, or bushing, 39, and rigidly held to said shaft by means of screw or pin 1 in hub 8. Hollow shaft 39 turns freely on shaft Q, connected to motor I21. Also mounted on hollow shaft 39.is split gear 28-28. The half 28 of split-gear 20-48 is rigidly attached to shaft 39 by means of pin or screw 65 in hub 64. Meshing with gear.2828 is another gear 26 rigidly mounted on-shaft 25 of television tuner 24 by mean of pin or screw 21 in the hub of said gear.

a Positioning arm 35 is rigidly held on shaft Q by means of screw E0 in hub H.

Spacer 20! on shaft Q, serves to limit the longitudina1 movement in one direction of hollow shaft 39 on shaft Q, and its movement in the opposite direction is arrested by c011ar-9,' having a set-screw 202.

Also rigidly mounted on shaft Q, is bevel gear 203 having a hub 204 and-a set-screw or pin 205. Gear 203 meshes with idlergear 200, which in turn meshes with bevel gear 201, rigidly mounted on hollow shaft 208 by means of screw or pin 209 in hub 2H0. Gear 207 is kept from meshing too tightly with bevel gear 205 by collar 2! i, rigidly mounted on shaft Q and abutting against hollow shaft 200 to which gear 201 is attached.

Shaft 208 transmits rotary motion to positioning arm 3? which is rigidly mounted on the other 2|9--2l9' is also rig dly mounted on shaft 2M by means of screw 220 in hub 22L Gear 222 meshes with gear 2l92I9-', and is affixed to'shaft 223 of. sound-signal tuner 224 by means of p n 225 in hub 226.

Discs A and C each carry a plurality of solenoids and plungers, or magnets with stationselector pins, the number of which should be from six to twenty per disc. These electro-responsive station seiect rs are desi natedbythe letter L, and

are individually distin uished by an additional letter and numeral. These selectors L must be anularly adiustab'e with n a few degrees about the enter of the d sc upon which they are mounted. The simplest way t do this. of course. would be t have them movable in arcs. but such an arran em 'it would subject their set-screws or other a-flixing means to the greatest strain when the discs are. be nz. rotated by means of a sidethrust appied to the pins or plungers Y. This strain is r duced, and other objectives served, by

making them movable along non-radial slots 221 or 228 extending from the outer part of the disc toward the center, as shown in Figs. 10 and 11. These non-radial slots should preferably be arranged so that any-two adjoining ones will both cross a radial line so that a selector placed near the outer end of one slot, as is LT2 in Fig. 10, may approach very close in angular degrees to another selector located near the inner end of an adjoining slot, as indicated by the position of LTI. As this specification proceeds, it will be evident that this provision is a great conven- Jence when using the automatic tuner fortwo stations that are very close on the tuning dial- Each selector may consist of the following parts; a magnet or solenoid 229, Figs. 9 and 10;

a plunger or pin Y, Figs. 9, l and 11, having a head 23l, Figs. 9 and a base 23!], Figs. 9 and 10, to which the solenoid 0r magnet is suitably attached; a bumper 232, Figs. 9 and 10, attached -to the base 239 and serving to prevent the spring 233, Fig, 9, from forcing the plunger or pin too far from its normal inoperative position; a small clamping plate 234, Figs. 9 and 11, located on the opposite side of the disc and having an aper- 25 ture 236, Figs. 9 and 11, to pass the pin Y; a guide 235, Figs. 9 and 11, which passes slidably through the slot in the, disc'and serves to hold the base and plate together; and a set-screw 231, Figs. 9, 10 and 11, to tighten the base and plate together firmly on the disc. For the sake of clearness in the drawing, various parts of selectors LT2, LT3, LR! and LR2 have been omitted. I

Fig. 11 shows the inner side of disc A, with the clamping plates, the magnets, of course, being located on the opposite side of the disc. It

will be noted in this fig'ure that the slots are closer to the center on disc A than on disc C. This is merely a precaution to keep protruding plunger pins on the two discs from colliding with each other.

To set the tuner, the sound and television stations are first tuned in by the tuning knobs 238 and 239. The rotation of knob 238 not only operates the tuner 224, but also turns gear 222, gear 2l9-2l9', hollow shaft 2| 4 and disc A. In like manner, the turning of knob 233 rotates. disc C to an angular position that is different for eachtelevision station. While the pair of associated sound broadcasting and television stations are thus tuned in, the set screw 231 is loosened on the selector on each disc that is nearest to the position that arms 35 and 31 are in when they close together. This is the'position shown in Figs. 9 and 11the position to which the arms are rotated when shaft Q, Fig. 9, turnsin the direction indicated by arrow 240. These selectors are then electrically connected to the switch 1 or push button that it is desired shall thereafter tune in this particular pair of stations. The total number of such station switches provided should equal the number of selectors on each disc, but

only three switches, 84a, 84b and 840 are shown in the figures.

In Fig. 9, selector LTI on disc C and selector LR3 on disc A are shown connected by wires 2 4i and 242 to contact 85c of switch 840. When this switch is actuated, the current passes from source 82 one side of which is grounded, through wire 244, motor I21, wire 83, switch 84c,'contact 85c; and. wires- 242 and 24! tov selectors LTI and LR3. The other side of the circuit is grounded to the disc and the various metal parts of the apparatus, a ground connection being shown at 243 at the extreme right. of the figure.

Thiscauses selectors LT! and LE3 to push out their plungers Yl and Y2 respectively and also starts the motor, which rotates shaft Q in the direction indicated by arrow 240, and by means of the in-' 5 terconnected parts previously explained, the arms 35 and 31 are caused to turn to the position shown in the drawing, with pins or plungers Yl and Y2 held-tightly between them. While they are thus held, the set-screws 231 are tight l0 ened firmly so that selectors LTI and LR3 will normally, occupy this position with respect to the arms 35 and 31 when these stations are tuned After the set-screws have been tightened,

15 switch 840 is released. Spring 245 connected to collar 9 by pin 246, and having the other end connected to a stationary pin 241, then rotates shaft Q in the direction indicated by the arrow on gear 203. This turns arm 35 in the same direction, and by means of the gears, turning in the direction indicated by the arrows, causes arm 31 to turn in an opposite direction to that of arm 35, They are prevented from making more than a half revolution by detent 248 on gear 201, which strikes against stopper 249 in the position of 248 shown in dotted lines. The inactive position of arms 35 and 31 is shown in dotted lines in Figs. 9 and 11.

When a pair of selectors have been set in the manner described, it will be evident that regardless of the angular position that discs A and C may occupy, the discs will be returned to the position in which they were set by merely clos- 'ing the proper switch, thus causing the plunger 35 pins to be ejected and turned with the discs until the pins are firmly held in place by the closing together of arms 35 and 31.

, Other selectors are similarly set for other paired stations and connected to other switches so that 40 each switch will control a pair of stations.

Each of the split gears mentioned in connection with Fig. 9 make it possible to avoid play between said gear and the meshing-gear, as the teeth on the two halves of thesplit gear are positioned by a spring so that they either spread between the teeth of the meshing gear or else each meshing tooth of the latter gear is tightly held between teeth on both halves of the split gear. In the figure, gear 28 is provided with a so tightly fitting or integral pin 250 which projects through a hole 25I in gear 28', this hole being larger than the diameter of the pin. Gear 28'. held against gear 28 by collar 254, has a pin 252 projecting from the same side of said gear as the '55 end ofpin 250 that protrudes through hole 25!.

A spring 253 draws these pin together, pulling the gears in opposite directions and causing teeth of gear 28 and the teeth of gear 28 to take up any play that would otherwise exist between these teeth and those of gear 26. The other split-gear 2 l 92 I 9' is similarly equipped.

For simplicity in the drawings,- motor I21 is shown connected directly to shaft Q, but in practice it is usually best to have intervening gears, or pulleys and belts, so that the motor may make several revolutions for each 'half revolution of shaft Q. Inasmuch as shaft .Q turns only 180 degrees, it is possible to use otherelectrical means than a motor to drive it.

Fig. 12'shows a modification in which the slots in the discs are radial and the arms 35 and 31 non-radial. 4 It will readily be seen that the movement of a selector along a slot will cause it-to occupy a difierent angular position when its pin '6 Y is grasped between the arms 35 and 31, and

that this modification accomplishes the same purposes as the arrangements shown in Figs. and 11.

Still other modifications may be made from the automatic tuning devices herein described without departing from the general nature and scope of the invention as set forth in the appended claims.

My claims are: I

1. In a radio tuning mechanism, a combination including: a rotatable control shaft; a positionable element adjustably mounted on said shaft; apositioning device arranged to engage said element upon movement toward said shaft;

optionally operable means for moving a part of said device from a rest position to a second po--;

sition, said means comprising a push button for optionally operating the same; and power-driven means responsive to the operation of said push button for engaging said part and causin said device to engage and move said element and r0- tate said shaft to an angular position determined by the adjustment ofsaid element thereon.

2. In a mechanism for angularly positioning a control element, a combination including: a ro- -tatable positionable member; a rotatable shaft;

3. In a radio tuning mechanism, a combination including: a positionable tuning control; a plurality of manually operable selectors; a plurality of motion-transmitting members each individual to one of said selectors and each comprising an engageable portion that moves, in response to the operation of said selector, from a rest position to an engageable position; a plurality of adjustable devices each operatively interposed between one of said members and said control; a power-driven rotatable engaging means acting in response to the operation of any of said selectors to engage the engageable portion of said selectors associated member when saidportion is in said engageable position and thereby move'said control to a position determined bythe adjustment of the associated device; and resilient means for returning the motion-transmitting members to a rest position.

ing the operation of the same; and rotatable means responsive to the operation of any of the manuals and common to all of said members 'for engaging any of said motion-transmitting members' in said second position and moving said control through the medium of the engaged member to. a position predetermined by the adjustment of the adjustable'device interposed between said angaged member and the control. I

' L. J. LEISHMAN. 

